Is the SCP the figure or the mist? You identify it as the figure and then go on to say that it's unclear if ithe figure's a biproduct or the source. If the figure's a biproduct, shouldn't the fog be the SCP? You need to be clearer.

"Terminated immediately" In some cases (e.g. virulent diseases) it's appropriate. In this case, it really isn't.

I'd expand a little bit more on the townspeople. People going missing off the face off the earth is creepy, but you could help it along by subtly implying their fate.

I was probably a bit too harsh in the way I originally phrased that. Let's try again: Scotch Mist. If there's a parody of your premise, it probably means it's been done to death. That's the point I was trying to make.

Ehhhh… I like the basic idea, for the same reasons I enjoyed Silent Hill. But then, there's Silent Hill. I think this idea is too derivative to stand a chance. Misty ghost towns are pretty well explored ground, even outside the SH series.